U.S. Pat. No. 2,956,187 to Wood discloses a flexible coupling means directed to the compensation for slight misalignment between a generator and an exciter shaft. Therefore, the general object of Wood is to eliminate slight misalignments of "several thousandths of an inch". The flexible coupling taught by Wood is a nested coupling to reduce the axial length of the connection between the generator and the exciter shaft. The coupling and damping means is placed on a small diameter of the exciter shaft in comparison with the maximum diameter of the generator. Therefore, the radial outer circumferential surface of the rubber sleeve of Wood is even too small to overcome torsion loads which might be caused when starting the generator.
Therefore the coupling means disclosed by Wood is not adapted to be used in heavy load slitting cutters because the Woo coupling is constructed for use in small synchronous generators, in which high tension forces and quick replacement of the damping means in case of repair is not relevant.
U.S. Pat. No. 2,880,599 to Hlinsky discloses a vibration damping gear comprising an arrangement of axially stacked resilient disks and annular disks which are alternately located in the arrangement. This arrangement is penetrated by a fastening bolt which effects an axial pressure onto the annular and resilient disks. Under consideration of heavy shear stresses the resilient disk as well as the bolts themselves may be damaged. Furthermore, a vibration damping means without any axial fastening means is disclosed. Here the resilient disks completely fill the radial space between an inner hub and a ring gear. However, although this vibration damping means allows larger torsion movements of the ring gear with respect to the inner hub, the damping gear is not constructed to be used in heavy load machines, where an abrupt blocking of a cutting wheel can cause serious damage to the wheel gear.
U.S. Pat. No. 4,467,753 to Lange discloses a vibration dampener on an engine shaft. The motor mount for the shaft is incorporated in a pulley device having a pulley concentric with and spaced from the shaft so that the vibrations of the shaft and engine are not transmitted to the pulley. The pulley is supported by a journal carried on the tractor frame and the pulley is connected to the shaft through an annular layer of elastomer material that is fixed to rotate both with the pulley and the shaft and which dampens any shaft or engine vibration that might otherwise be transmitted to the pulley and to the frame. Even this vibration dampener is constructed for dampening little shocks, e.g. when starting the engine, and is therefore not able to dampen and transfer heavy shock loads as they appear in operation of a slitting cutter.